As is described, for example, in the under-mentioned patent citation 1 which corresponds to an application filed by the same applicant as the present application, as one of friction brake devices, a friction brake device has been known in which friction members that are pressed against a rotor disk are rotatable about an autorotation axis parallel to the rotation axis of the rotor disk. In this disk type brake device, a braking torque is generated by means of revolution of the friction members around the rotation axis relative to the rotor disk and a resistance torque is generated by means of autorotation of the friction members about the autorotation axis relative to the rotor disk. Another braking torque is generated by means of the resistance torque being transmitted to the rotor disk by a gear device.
According to a brake device described in the above-mentioned patent citation 1, as compared to a conventional general brake device in which a braking torque is generated only by means of the friction members revolving relative to the rotor disk, a braking force can be increased. In particular, a braking force can be increased without increasing the pressing force with which the friction members are pressed against the rotor disk by pressing devices.